Long Runs – The Cornerstone of Distance Running

By Rick Morris

Sit back, relax and close your eyes. Now just let the concept of distance running play like a movie in your head. You probably have an image in your mind of yourself or an imaginary athlete running long distances over a serene trail or road. The first workout that comes to mind when you think about distance running is very likely your weekly long run. It’s those long distance runs that build up the base of endurance that’s so important to every distance runner no matter what their goal or experience level. For a beginning runner long endurance runs improve their VO2 max, muscular strength, endurance and even lactate turn point. A more experienced or competitive runner’s needs these long efforts to develop slow twitch muscle fibers, carbohydrate storage capacity and muscle impact resistance.

These long and, for the most part, easy runs improve your endurance and running fitness in a number of ways:

Long Runs Build More Mitochondria

Long runs and endurance training increase the number of mitochondria in your working muscles. Mitochondria are very small structures in your muscle cells where energy production takes place. When you build more mitochondria you increase your ability to extract oxygen and nutrients from your blood, produce energy and improve your endurance.

Long Runs Increase Your Capillary Density

Capillaries are small blood vessels that supply oxygen and nutrients to your muscle cells. Endurance training builds more capillaries which mean you get improved flow of oxygen and other important nutrients to your muscles cells. As a result your endurance and running fitness improves.

Endurance Training Increase Your Blood Volume

Long runs build more red blood cells. Red blood cells pick up oxygen from your lungs and deliver it to your muscle cells. When you have more red blood cells your body is able to deliver more oxygen to your muscle cells and improve your endurance, fitness and running performance.

Long Runs Develop Your Slow Twitch Muscle Fibers

You were born with a genetically pre determined ration of muscle fibers. Muscle fibers are either slow twitch or fast twitch. Slow twitch fibers (type 1) have more endurance while fast twitch fibers (type 2) produce more power. Marathon runners use predominately slow twitch fibers because of their greater endurance potential. World class sprinters will have more fast twitch fibers while top level distance runners were born with more slow twitch fibers. Endurance training develops your slow twitch muscle fibers. No only do long runs develop your existing slow twitch fibers, they also can also make a specific type of fast twitch muscle fiber (type 2A) behave like a slow twitch fiber.

Long Runs Will Build You a Bigger, Better Fuel Tank

As a distance runner your primary source of fuel is carbohydrates. If you can store more carbohydrates you will be able to run longer before you become fatigued. Endurance training increases your muscles ability to store carbohydrates. When you perform a long run you begin to deplete your muscular stores of carbohydrates. This depletion sends a notice to your body that it need to store more. As a result your muscles learn to store more carbohydrates to fuel your long runs. In essence you build a bigger fuel tank.

Improve Impact Resistance

A typical runner takes around 42,000 steps during the course of a full marathon. Depending upon how efficiently you run, you are placing somewhere between 1.5 and 4 times your body weight on your leg muscles and joints with each step. Taking an average of 2 times your body weight, the muscles, tendons and joints of a 150 pound runner will absorb almost 13 million pounds of impact during a marathon! That is a lot of stress even for the most efficient and advanced runner.
Improving the ability of your muscles, tendons and bones to withstand all that stress is one of most critical goals of distance training and long running. When your muscles and tendons are placed under stress they breakdown slightly. They respond to that minor damage by rebuilding themselves even stronger than before. That is why you get stronger through progressively longer training.

How Often Should You Go Long?

I am asked three questions concerning long runs by nearly every client I coach. The first of those is how often should I do a long run? There is no one specific answer to any coaching question. Running isn’t a “one size fits all” world. You need to tailor your workouts and training program to your specific goals and experience level. The generic answer to the question of how often to do a long run is either once per week or once every two weeks. Most well trained distance runners can do a long run every week. The exception to this is during marathon training when you begin to do very long run or goal pace long runs. During hard marathon training you would be better of alternating a very long run or goal pace long run one week with either a moderate distance long run or long tempo run the following week.

How Far Should You Run?

This is the second question I am usually asked. The length of your long run is very dependant upon your experience level and your training goal. More experienced and fit runners should do long runs of between 15 and 25 miles. A long run to a beginning runner may be a short as 3 to 4 miles early in their training. In the chart below I have listed my recommendations for long run distances.

Does Long Run Pace Matter?

This last question has the really vague answer of yes and no. In some cases your running pace is quite important and at other times your pace isn’t critical. For general long runs you should run at a pace that simply feels easy. You shouldn’t be struggling. Most easy long runs are done at between 30 seconds per mile slower than marathon pace and 1 minute 30 seconds slower. But don’t pay too much attention to your watch, just run at a pace that feels relatively easy.

There are times when your pace becomes important. The first of those is during goal pace long runs. The most obvious example is marathon pace long runs. Marathon goal pace running is a critical part of marathon training if your goal is to race the marathon or finish in a specific time. These goal pace runs improve your ability to hold goal pace when fatigued. See goal pace marathon runs for more examples. You can also goal pace long runs for any distance including 5K goal pace long runs and 10K goal pace long runs.